1 files changed, 22 insertions, 18 deletions

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index ef6f6c62dfee..39d641292579 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -807,6 +807,7 @@ typedef struct {
 struct pagemapread {
         int pos, len;
         pagemap_entry_t *buffer;
+        bool v2;
 };
 
 #define PAGEMAP_WALK_SIZE       (PMD_SIZE)
@@ -820,14 +821,16 @@ struct pagemapread {
 #define PM_PSHIFT_BITS      6
 #define PM_PSHIFT_OFFSET    (PM_STATUS_OFFSET - PM_PSHIFT_BITS)
 #define PM_PSHIFT_MASK      (((1LL << PM_PSHIFT_BITS) - 1) << PM_PSHIFT_OFFSET)
-#define PM_PSHIFT(x)        (((u64) (x) << PM_PSHIFT_OFFSET) & PM_PSHIFT_MASK)
+#define __PM_PSHIFT(x)      (((u64) (x) << PM_PSHIFT_OFFSET) & PM_PSHIFT_MASK)
 #define PM_PFRAME_MASK      ((1LL << PM_PSHIFT_OFFSET) - 1)
 #define PM_PFRAME(x)        ((x) & PM_PFRAME_MASK)
+/* in "new" pagemap pshift bits are occupied with more status bits */
+#define PM_STATUS2(v2, x)   (__PM_PSHIFT(v2 ? x : PAGE_SHIFT))
 
 #define PM_PRESENT          PM_STATUS(4LL)
 #define PM_SWAP             PM_STATUS(2LL)
 #define PM_FILE             PM_STATUS(1LL)
-#define PM_NOT_PRESENT      PM_PSHIFT(PAGE_SHIFT)
+#define PM_NOT_PRESENT(v2)  PM_STATUS2(v2, 0)
 #define PM_END_OF_BUFFER    1
 
 static inline pagemap_entry_t make_pme(u64 val)
@@ -850,7 +853,7 @@ static int pagemap_pte_hole(unsigned long start, unsigned long end,
         struct pagemapread *pm = walk->private;
         unsigned long addr;
         int err = 0;
-        pagemap_entry_t pme = make_pme(PM_NOT_PRESENT);
+        pagemap_entry_t pme = make_pme(PM_NOT_PRESENT(pm->v2));
 
         for (addr = start; addr < end; addr += PAGE_SIZE) {
                 err = add_to_pagemap(addr, &pme, pm);
@@ -860,7 +863,7 @@ static int pagemap_pte_hole(unsigned long start, unsigned long end,
         return err;
 }
 
-static void pte_to_pagemap_entry(pagemap_entry_t *pme,
+static void pte_to_pagemap_entry(pagemap_entry_t *pme, struct pagemapread *pm,
                 struct vm_area_struct *vma, unsigned long addr, pte_t pte)
 {
         u64 frame, flags;
@@ -879,18 +882,18 @@ static void pte_to_pagemap_entry(pagemap_entry_t *pme,
                 if (is_migration_entry(entry))
                         page = migration_entry_to_page(entry);
         } else {
-                *pme = make_pme(PM_NOT_PRESENT);
+                *pme = make_pme(PM_NOT_PRESENT(pm->v2));
                 return;
         }
 
         if (page && !PageAnon(page))
                 flags |= PM_FILE;
 
-        *pme = make_pme(PM_PFRAME(frame) | PM_PSHIFT(PAGE_SHIFT) | flags);
+        *pme = make_pme(PM_PFRAME(frame) | PM_STATUS2(pm->v2, 0) | flags);
 }
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-static void thp_pmd_to_pagemap_entry(pagemap_entry_t *pme,
+static void thp_pmd_to_pagemap_entry(pagemap_entry_t *pme, struct pagemapread *pm,
                                         pmd_t pmd, int offset)
 {
         /*
@@ -900,12 +903,12 @@ static void thp_pmd_to_pagemap_entry(pagemap_entry_t *pme,
          */
         if (pmd_present(pmd))
                 *pme = make_pme(PM_PFRAME(pmd_pfn(pmd) + offset)
-                                | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT);
+                                | PM_STATUS2(pm->v2, 0) | PM_PRESENT);
         else
-                *pme = make_pme(PM_NOT_PRESENT);
+                *pme = make_pme(PM_NOT_PRESENT(pm->v2));
 }
 #else
-static inline void thp_pmd_to_pagemap_entry(pagemap_entry_t *pme,
+static inline void thp_pmd_to_pagemap_entry(pagemap_entry_t *pme, struct pagemapread *pm,
                                                 pmd_t pmd, int offset)
 {
 }
@@ -918,7 +921,7 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
         struct pagemapread *pm = walk->private;
         pte_t *pte;
         int err = 0;
-        pagemap_entry_t pme = make_pme(PM_NOT_PRESENT);
+        pagemap_entry_t pme = make_pme(PM_NOT_PRESENT(pm->v2));
 
         /* find the first VMA at or above 'addr' */
         vma = find_vma(walk->mm, addr);
@@ -928,7 +931,7 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
 
                         offset = (addr & ~PAGEMAP_WALK_MASK) >>
                                         PAGE_SHIFT;
-                        thp_pmd_to_pagemap_entry(&pme, *pmd, offset);
+                        thp_pmd_to_pagemap_entry(&pme, pm, *pmd, offset);
                         err = add_to_pagemap(addr, &pme, pm);
                         if (err)
                                 break;
@@ -945,7 +948,7 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
                  * and need a new, higher one */
                 if (vma && (addr >= vma->vm_end)) {
                         vma = find_vma(walk->mm, addr);
-                        pme = make_pme(PM_NOT_PRESENT);
+                        pme = make_pme(PM_NOT_PRESENT(pm->v2));
                 }
 
                 /* check that 'vma' actually covers this address,
@@ -953,7 +956,7 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
                 if (vma && (vma->vm_start <= addr) &&
                     !is_vm_hugetlb_page(vma)) {
                         pte = pte_offset_map(pmd, addr);
-                        pte_to_pagemap_entry(&pme, vma, addr, *pte);
+                        pte_to_pagemap_entry(&pme, pm, vma, addr, *pte);
                         /* unmap before userspace copy */
                         pte_unmap(pte);
                 }
@@ -968,14 +971,14 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
 }
 
 #ifdef CONFIG_HUGETLB_PAGE
-static void huge_pte_to_pagemap_entry(pagemap_entry_t *pme,
+static void huge_pte_to_pagemap_entry(pagemap_entry_t *pme, struct pagemapread *pm,
                                         pte_t pte, int offset)
 {
         if (pte_present(pte))
                 *pme = make_pme(PM_PFRAME(pte_pfn(pte) + offset)
-                                | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT);
+                                | PM_STATUS2(pm->v2, 0) | PM_PRESENT);
         else
-                *pme = make_pme(PM_NOT_PRESENT);
+                *pme = make_pme(PM_NOT_PRESENT(pm->v2));
 }
 
 /* This function walks within one hugetlb entry in the single call */
@@ -989,7 +992,7 @@ static int pagemap_hugetlb_range(pte_t *pte, unsigned long hmask,
 
         for (; addr != end; addr += PAGE_SIZE) {
                 int offset = (addr & ~hmask) >> PAGE_SHIFT;
-                huge_pte_to_pagemap_entry(&pme, *pte, offset);
+                huge_pte_to_pagemap_entry(&pme, pm, *pte, offset);
                 err = add_to_pagemap(addr, &pme, pm);
                 if (err)
                         return err;
@@ -1051,6 +1054,7 @@ static ssize_t pagemap_read(struct file *file, char __user *buf,
         if (!count)
                 goto out_task;
 
+        pm.v2 = false;
         pm.len = PM_ENTRY_BYTES * (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
         pm.buffer = kmalloc(pm.len, GFP_TEMPORARY);
         ret = -ENOMEM;